School of Engineering and Information Technology

Supersonic flows over shallow cavities

(Sridhar, Gai, Kleine)

The study of compressible cavity flow has been an important topic in the field of aerodynamics and acoustics. Cavity flows are encountered in essentially all moving vehicles, from automobiles to aircraft to missiles. These cavities are present in the aircraft in the form of weapon bays, landing doors etc. Although the geometry of these cavities is simple, their unsteady fluid dynamic behaviour is complicated and difficult to predict both in subsonic and supersonic flows. These fluid phenomena typically cause unwanted drag, structural noise and vibrations.

The results show that the flow undergoes a significant structural change when L/D is increased beyond about 5. Cavities with L/D < 5 show a highly unsteady oscillatory structure while those with L/D > 5 exhibit a steady oscillatory flow within the cavity. This has important implications with regard to noise and vibrations of a structure that incorporates cavities in its design.

Two streamline plots for the case of L/D = 3: the flow field is characterised by the presence of a number of unsteady vortices.

 Return to High Speed Flows and Microfluidics homepage
 Return to Research homepage

Other research projects for High Speed Flows and Microfluidics during 2012:

 SCRAMSPACE supersonic combustion flight test
 Free flying models in hypersonic facilities
 CARS measurements of electric field strength in gases
 Simulation of hypersonic separated flows
 Fluid-Structure Interaction of Gas Turbine Blades
 Shock reflection off cylindrical surfaces
 Simulation and measurement of fluid-thermalstructural behaviour of hypersonic vehicles
 Fluidic Thrust Control
 Modelling of flow in a micro-hydrocyclone
 Experimental study of cutting forces in micro end-milling
 Investigation on the droplet formation time with xanthan gum solutions at a t-junction